Xerospermum topengii Merrill, Philipp. J. Sci. 23: 250. 1923; Nephelium chryseum Blume var. topengii (Merrill) C. Y. Wu; N. lappaceum Linnaeus var. topengii (Merrill) F. C. How & C. N. Ho.

Trees, evergreen, 5-20 m tall. Branches reddish brown when dry, often pilosulose. Leaflets 2-4 pairs; petiolules 5-8 mm; blades oblong or oblong-lanceolate, 6-18 × 2.5-7.5 cm, thinly leathery, glaucous, pilose abaxially, lateral veins 10-15 pairs, straight, nearly parallel, base slightly obtuse to broadly cuneate, margin entire, apex acute. Inflorescences and flowers similar to N. chryseum. Fruit reddish yellow, ellipsoid, including spines ca. 3 × 2 cm, spines 3.5-5 mm.

This species is used for its timber.

● Forests. Hainan.